The Stovebolt Site Forums The Shop Area Engine Shop 58-59 235 hydraulic lifters valve adjustment

I'm sure this has been discussed many times but once more please. I have a rebuilt 58/59 Chevy 235 that came with hydraulic lifters. My 41 through 56 shop manuals only deal with adjusting valves with solid lifters. Tightening the rocker arm adjusting screws (engine not running)beyond the point of contact with the valve stem led to zero compression on my compression tester. It would seem to me that additional pressure should compress the lifter, not hold the valve open. I'm only talking 3/4 of a turn here. This is a freshly rebuilt engine ready for its first coaxing to life. I got it to run today briefly but only 90-100psi per cylinder. That seems anemic to me for a fresh rebuild and I suspect the valves. Feedback anyone?